Gone are the purple rinses. The Isle of Wight is the new black - or should I say green? It surfs, it sculpts, it sings and it shouts sustainability. It also would have cost the best part of a hundred quid to get there by car ferry the weekend I wanted to travel, which encouraged me to go green and leave the car at home. It was cheaper for my family to travel by train from London with a family railcard.

The island even has an eco-friendly tourism website with suggestions on how to enjoy this beautiful place without destroying what it has to offer. A website which adds 'chilling' to its list of activities wins my vote straight away.

I booked the Shack, a cute little beach chalet a few miles from Cowes, arranged bike hire through a company which delivers and collects wherever you want, studied cycle maps into the early hours and obsessed over five-day weather forecasts. Then, two-and-a-half hours after leaving home, we were lashing across the Solent on Red Funnel's high-speed catamaran. This is not the cheapest option, but it is only a 20-minute crossing and worth the look on my children's faces as we took off. It was so fast I was slightly concerned it wasn't going to stop. But we settled gently into the quay at West Cowes, where John, the bike guy, gave us our bikes and took our luggage, to be dropped to us later at the chalet. The island is cyclist heaven. Just enough hills to push yourself, or your bike and tagged-on four-year-old in my case, and varied landscapes of coast, forest and estuarine marshes.

The Shack is a gloriously simple wooden summerhouse, painted in pastel blue and white, overlooking a buttercup-filled meadow dipping down to a quiet sandy beach. A pre-ordered hamper of island goodies awaited the hungry cyclists, enabling us to prepare a gastronomic evening picnic watching the sunset over the bay. The menu included locally made pasta served with confit de tomates from the Garlic Farm here on the island. To drink, we had a chilled rosé from the local Rossiters Vineyard, and island-made apple juice.

The children leapt onto the swingseat hanging from an oak tree in the garden and I had to blink twice to check I was not on the set of a Boden photo shoot. Our dusty backpacks and sweaty trainers suddenly looked out of place among the collection of carefully chosen vintage bric-a-brac and funky 1950s furniture. But Helen, the owner with the enviable designer eye, is not precious about her vision - it is a place for having good old-fashioned fun. With its solar-powered lighting, no mains electricity, wood-burning stove amply supplied with driftwood, composter, recycling, and environment-friendly cleaning products provided, this ticks many of the green boxes. And the solar-powered mobile-phone charger is inspired.

It would not be difficult to fill your days doing nothing at the Shack. Buckets, spades and fishing nets were provided; my sons cycled safely up and down the lane, chased butterflies across the meadow, and swam several times a day. But I couldn't resist some of the other activities. One day we took a two-mile cycle to riding stables for the boys' first horse-riding experience. Hugo, my youngest, had been talking for weeks about riding on a unicorn, so when Faye the farmer led the most perfect white pony towards a seldom-silenced four-year-old, there was no explanation needed for why it didn't have a horn sticking out of its head. As far as he was concerned, his dream had come true.

There were many such highlights on this trip: putting coffee on to brew, and hopping down for an early morning swim watched only by onlooking curlews; cycling in nearby Parkhurst Forest and spotting red squirrels. But the big high was saved for last. We took our final view of our new favourite place from the top of a 60ft ancient oak tree. Guided by a New Zealand arborist, Paul, who confesses he would rather preserve and climb trees than follow his original career path of cutting them down, we donned our harnesses and helmets, and I prayed for a head for heights. There was no reason to fear. I watched Louis, my eight-year-old, climb like a dancer from branch to branch, handling knots and carabiner clips like an expert. My climbing was more baboon than Darcey Bussell, but I finally caught up with him lying high up in a tree hammock eating the chocolate eggs which awaited him. We lay in the hammock together, swaying gently with the breeze and the world seemed to stop for a while.

After three hours of climbing, we headed back to the ferry. We locked our bikes by the jetty, and waited for our bags to be delivered back to us. They were running a bit late, but I wasn't worried about catching the boat as they run every half hour. In fact, I realised that something had happened to the uptight London timekeeper in me. I really didn't care. Or, as they say on the Isle of Wight, I had finally chilled.

More eco-friendly breaks

Built from sustainable timber, with grass growing on the roofs for insulation, and green energy supplies, the Aislabeck Lodges in Richmond, North Yorkshire, tick all the green boxes. Glass walls give glorious views across the Vale of York. The four lodges each have a double bedroom, two singles, and a pull-out guest bed. It's a great base for exploring on foot or bike. A week costs £863.

From clearing canals in Nottingham to woodland management in East Sussex, the British Trust for Conservation Volunteers (BTVC) has a range of breaks for green holidaymakers. Sign up for its week-long dry-stone walling holiday in the Durham Dales and you'll even earn a qualification.

Hire a luxurious log cabin at Woodside Lodges country park in Herefordshire's pretty Malvern Hills. The area has won a string of conservation awards and the countryside is great for outdoor adventure: the woods are dotted with lakes and waterfalls and it's perfect hiking terrain. Nearby attractions include the market town of Ledbury and imposing Eastnor Castle. Ledbury Lodge sleeps up to six people and costs from £450.

Join a 12-day whale and dolphin-watching expedition with Earthwatch in the Outer Moray Firth, north-east Scotland, for an exhilarating holiday that also helps conservation efforts. The warm and cold waters of the Atlantic and Arctic oceans meet here, providing rich feeding grounds for 22 species of whale and dolphin - the only population of bottlenose dolphins in the North Sea is found here. You'll be trained to identify species and take to the water in inflatables to record data on behaviour. Expeditions run in June, July and September and cost £750 with accommodation, food and training.